Matrix metalloproteinases and their inhibitors in gestational trophoblastic diseases and normal placenta

Gestational choriocarcinoma

Gestational choriocarcinoma accounts for 5% of gestational trophoblastic neoplasms. Approximately 50%, 25%, and 25% of gestational choriocarcinoma occur after molar pregnancies, term pregnancies, and other gestational events, respectively. The FIGO scoring system categorizes patients into low (score 0 to 6) and high risk (score 7 or more) choriocarcinoma. Single-agent and multi-agent chemotherapy are used in low- and high-risk patients, respectively. Chemotherapy for localized disease has a goal of eradication of disease without surgery and is associated with favorable prognosis and fertility preservation. Most patients with gestational choriocarcinoma are cured with chemotherapy; however, some (<5.0%) will die as a result of multi-drug resistance, underscoring the need for novel approaches in this group of patients. Although there are limited data due to its rarity, the treatment response with immunotherapy is high, ranging between 50-70%. Novel combinations of immune checkpoint inhibitors with targeted therapies (including VEGFR-2 inhibitors) are under evaluation. PD-L1 inhibitors are considered a potential important opportunity for chemo-resistant patients, and to replace or de-escalate chemotherapy to avoid or minimize chemotherapy toxicity. In this review, the Rare Tumor Working Group and the European Organization for Research and Treatment of Cancer evaluated the current landscape and further perspective in the management of patients diagnosed with gestational choriocarcinoma.

Measurement of Human Chorionic Gonadotrophin in Women with Gestational Trophoblastic Disease

OBJECTIVES

The objective of this study was to collect information on human chorionic gonadotrophin (hCG) laboratory testing and reporting in women with gestational trophoblastic disease (GTD), to assess the associated challenges, and to offer perspectives on hCG testing harmonisation.

DESIGN

Information was collected from laboratories by electronic survey (SurveyMonkey) using a questionnaire designed by members of the European Organisation for the Treatment of Trophoblastic Disease (EOTTD) hCG working party.

PARTICIPANTS

The questionnaire was distributed by the EOTTD board to member laboratories and their associated scientists who work within the GTD field.

SETTING

The questionnaire was distributed and accessed via an online platform.

METHODS

The questionnaire consisted of 5 main sections. These included methods used for hCG testing, quality procedures, reporting of results, laboratory operational aspects, and non-GTD testing capability. In addition to reporting these survey results, examples of case scenarios which illustrate the difficulties faced by laboratories providing hCG measurement for GTD patient management were described. The benefits and challenges of using centralised versus non-centralised hCG testing were discussed alongside the utilisation of regression curves for management of GTD patients.

RESULTS

Information from the survey was collated and presented for each section and showed huge variability in responses across laboratories even for those using the same hCG testing platforms. An educational example was presented, highlighting the consequence of using inappropriate hCG assays on clinical patient management (Educational Example A), along with an example of biotin interference (Educational Example B) and an example of high-dose hook effect (Educational Example C), demonstrating the importance of knowing the limitations of hCG tests. The merits of centralised versus non-centralised hCG testing and use of hCG regression curves to aid patient management were discussed.

LIMITATIONS

To ensure the survey was completed by laboratories providing hCG testing for GTD management, the questionnaire was distributed by the EOTTD board. It was assumed the EOTTD board held the correct laboratory contact, and that the questionnaire was completed by a scientist with in-depth knowledge of laboratory procedures.

CONCLUSIONS

The hCG survey highlighted a lack of harmonisation of hCG testing across laboratories. Healthcare professionals involved in the management of women with GTD should be aware of this limitation. Further work is needed to ensure an appropriate, quality-assured laboratory service is available for hCG monitoring in women with GTD.

Modulation of matrix metalloproteases by ciliary neurotrophic factor in human placental development

Ciliary neurotrophic factor (CNTF) is a pleiotropic cytokine that signals through a receptor complex containing a specific subunit, CNTF receptor α (CNTFRα). The two molecules are constitutively expressed in key structures for human placental growth and differentiation. The possible role of CNTF in enhancing cell proliferation and/or invasion during placental development and remodelling was investigated using HTR-8/SVneo and BeWo cells, taken respectively as cytotrophoblast and syncytiotrophoblast models. In both cell lines, treatment with human recombinant (hr) CNTF activated JAK2/STAT3 signalling and inhibited the ERK pathway. Interestingly, in HTR-8/SVneo cells, 50 ng hrCNTF induced significant downregulation of matrix metalloprotease (MMP)-1 and significant upregulation of MMP-9. Moreover, pharmacological inhibition of JAK2/STAT3 signalling by AG490 and curcumin resulted in MMP-9 downregulation; it activated the ERK signalling pathway and upregulated MMP-1 expression. Collectively, these data suggest a role for CNTF signalling in extravillous cytotrophoblast invasion through the modulation of specific MMPs.

Gestational trophoblastic neoplasms (GTNs) do not display epithelial-to-mesenchymal transition (EMT) features

Although epithelial-to-mesenchymal transition (EMT) has been described in the development of complete hydatidiform moles and the invasion of the maternal decidua by trophoblasts during normal human placentation, its implication in gestational trophoblastic neoplasm (GTN) without villi is totally unknown. We studied the immunoexpression of EMT transcription factors (TWIST1, ZEB1, ZEB2), E-cadherin, and vimentin in 18 trophoblastic tumors and pseudo-tumors. Weak nuclear TWIST1 immunostaining was seen in 5% to 10% of all trophoblastic cells, without ZEB1 and ZEB2 nuclear staining. Trophoblastic cells did not express vimentin, and the expression of E-cadherin was maintained in all cases, indicating the absence of EMT features in GTN.

What is the role of matrix metalloproteinase-2 in placenta percreta?

AIM

This study compared the placental expression of the matrix metalloproteinase-2 (MMP-2) enzyme, which is thought to play a key role in the penetration of trophoblastic cells, in third-trimester placenta percreta (PP) patients with that of women with normal pregnancies.

METHODS

Twenty-five pregnant subjects who underwent cesarean section due to PP and 25 term pregnant subjects who underwent cesarean section for obstetric reasons were included in the study. Demographic data, pathology reports, and histopathological samples were examined. Blocks containing samples of placenta underwent immunohistochemical analysis using the MMP-2 antibody. Immunohistochemical expression of placental samples obtained from both groups was examined and compared.

RESULTS

There were no statistically significant differences in the demographic data (P > 0.05). With regard to immunohistochemistry, cytoplasmic staining of trophoblastic cells was considered immunohistochemically positive. In the PP tissue samples, positive MMP-2 staining was detected as follows: 0 immunoreactivity, one patient (4%); 1(+), six patients (24%); 2(+), seven patients (28%); and 3(+), 11 patients (44%). In the term pregnant placental tissue samples, positive MMP-2 staining was detected in five patients (20%) at 0 immunoreactivity, 12 (48%) at 1(+) immunoreactivity, five (20%) at 2(+) immunoreactivity, and three patients (12%) at 3(+) immunoreactivity. Immunohistochemical expression was significantly different between the PP and normal term pregnancy placental tissues (P = 0.02).

CONCLUSION

The stronger expression of the MMP-2 enzyme in the PP as compared to the normal placental tissue suggests that this enzyme may be an effective mediator in the pathogenesis of PP.

p21-Activated kinase-1 promotes aggressive phenotype, cell proliferation, and invasion in gestational trophoblastic disease

Gestational trophoblastic disease (GTD) includes hydatidiform mole (HM), which can develop persistent gestational trophoblastic neoplasia requiring chemotherapy; choriocarcinoma, which is a frankly malignant tumor; placental site trophoblastic tumor; and epithelioid trophoblastic tumor. p21-Activated kinases (PAKs) promote malignant tumor progression. Therefore, this study investigated PAK1, PAK2, and p-PAK2 Ser(20) in the pathogenesis of GTD. By real-time PCR, PAK1 mRNA was significantly higher in HMs, particularly metastatic HMs (P = 0.046) and HMs that developed persistent disease (P = 0.011), when compared with normal placentas. By immunohistochemistry, significantly increased cytoplasmic PAK1 immunoreactivity in cytotrophoblasts was also detected in HMs (P = 0.042) and choriocarcinomas (P = 0.003). In addition, HMs that developed persistent disease displayed higher PAK1 immunoreactivity than those that regressed (P = 0.016), and elevated PAK1 immunoreactivity was observed in placental site trophoblastic tumors. Indeed, there was significant positive correlation between PAK1 expression and the proliferative indices Ki-67 (P = 0.016) and MCM7 (P = 0.026). Moreover, higher PAK1 mRNA and protein expression was confirmed in the choriocarcinoma cell-lines JEG-3 and JAR; however, PAK2 mRNA and p-PAK2 immunoreactivity showed a similar expression pattern in normal first trimester placentas and GTD. Knockdown of PAK1 in JEG-3 and JAR reduced cell proliferation, migration, and invasion ability, up-regulated p16, and down-regulated vascular endothelial growth factor and MT1-MMP expression. This is the first report revealing the involvement of PAK1 in the pathogenesis and clinical progress of GTD.

Cellular and molecular regulation of spiral artery remodelling: lessons from the cardiovascular field

A number of important changes take place in the maternal uterine vasculature during the first few weeks of pregnancy resulting in increased blood flow to the intervillous space. Vascular endothelial and smooth muscle cells are lost from the spiral arteries and are replaced by fetal trophoblast cells. Failure of the vessels to remodel sufficiently is a common feature of pregnancy pathologies such as early pregnancy loss, intrauterine growth restriction and pre-eclampsia. There is evidence to suggest that some vascular changes occur prior to trophoblast invasion, however, in the absence of trophoblasts remodelling of the spiral arteries is reduced. Until recently our knowledge of these events has been obtained from immunohistochemical studies which, although extremely useful, can give little insight into the mechanisms involved. With the development of more complex in vitro models a picture of events at a cellular and molecular level is beginning to emerge, although some caution is required in extrapolating to the in vivo situation. Trophoblasts synthesise and release a plethora of cytokines and growth factors including members of the tumour necrosis factor family. Studies suggest that these factors may be important in regulating the remodelling process by inducing both endothelial and vascular smooth muscle cell apoptosis. In addition, it is evident from studies in other vascular beds that the structure of the vessel is influenced by factors such as flow, changes in the composition of the extracellular matrix, the phenotype of the vascular cells and the local immune cell environment. It is the aim of this review to present our current knowledge of the mechanisms involved in spiral artery remodelling and explore other possible pathways and cellular interactions that may be involved, informed by studies in the cardiovascular field.

Regulation of extravillous trophoblast invasion by uterine natural killer cells is dependent on gestational age

BACKGROUND

Extravillous trophoblast (EVT) cell invasion of uterine decidua and the inner third of myometrium is critical for successful pregnancy. Many decidual factors are likely to play a role in regulating this process. We have previously shown that cytokines, known to be produced by uterine natural killer (uNK) cells, such as TNF-alpha, TGF-beta1 and IFN-gamma inhibit EVT invasion. We therefore hypothesized that supernatants from purified uNK cells would inhibit EVT invasion.

METHODS AND RESULTS

Total unfractionated decidual cell supernatants from 8 to 10 weeks gestation increased EVT invasion from placental villous explants, although uNK cell supernatants from 8 to 10 weeks gestation had no effect. In contrast, both total decidual and uNK cell supernatants from 12 to 14 weeks gestation stimulated EVT invasion. MMP-2, uPA, PAI-1 and PAI-2 levels did not differ under any of the conditions tested, whereas MMP-9 levels were increased in the presence of both total decidual and uNK cell supernatants from both gestational age groups. There was a decrease in the level of EVT apoptosis in the presence of uNK cell supernatant from 12 to 14 weeks, but not 8-10 weeks, gestation.

CONCLUSIONS

Decidual uNK cell supernatants from 12 to 14 weeks gestational age stimulated EVT invasion, potentially by increasing MMP9 levels and reducing apoptosis. Total decidual cell isolates stimulated EVT invasion at both gestational ages investigated, potentially reflecting the complex nature of these cell culture supernatants.

Pathogenesis of choriocarcinoma: clinical, genetic and stem cell perspectives

Choriocarcinoma is a unique malignant neoplasm composed of mononuclear cytotrophoblasts and multinucleated syncytiotrophoblasts that produce human chorionic gonadotrophin. Choriocarcinoma can occur after a pregnancy, as a component of germ cell tumors, or in association with a poorly differentiated somatic carcinoma, each with distinct clinical features. Cytogenetic and molecular studies, predominantly on gestational choriocarcinoma, revealed the impact of oncogenes, tumor suppressor genes and imprinting genes on its pathogenesis. The role of stem cells in various types of choriocarcinoma has been studied recently. This review will discuss how such knowledge can enhance our understanding of the pathogenesis of choriocarcinoma, enable exploration of novel anti-choriocarcinoma targeted therapy and possibly improve our insight on embryological and placental development.

Overexpression of NANOG in gestational trophoblastic diseases: effect on apoptosis, cell invasion, and clinical outcome

Gestational trophoblastic disease includes choriocarcinoma, a frankly malignant tumor, and hydatidiform mole (HM), which often leads to the development of persistent gestational trophoblastic neoplasia and requires chemotherapy. NANOG is an important transcription factor that is crucial for maintaining embryonic stem cell self-renewal and pluripotency. We postulated that NANOG is involved in the pathogenesis of gestational trophoblastic disease. In this study, significantly higher NANOG mRNA and protein expression levels, by quantitative PCR and immunoblotting, respectively, were demonstrated in HMs, particularly those that developed persistent disease, when compared with normal placentas. In addition, significantly increased nuclear NANOG immunoreactivity was found by immunohistochemistry in HMs (P < 0.001) and choriocarcinoma (P = 0.002). Higher NANOG expression levels were demonstrated in HMs that developed persistent disease, as compared with those that regressed (P = 0.025). Nuclear localization of NANOG was confirmed by confocal microscopy and immunoblotting in choriocarcinoma cell lines. There was a significant inverse correlation between NANOG immunoreactivity and apoptotic index assessed by M30 CytoDeath antibody (P = 0.012). After stable knockdown of NANOG in the choriocarcinoma cell line JEG-3 by an shRNA approach, increased apoptosis was observed in relation to with enhanced caspases and poly(ADP-ribose) polymerase activities. NANOG knockdown was also associated with decreased mobility and invasion of JEG-3 and down-regulation of matrix metalloproteases 2 and 9. These findings suggest that NANOG is involved in the pathogenesis and clinical progress of gestational trophoblastic disease, likely through its effect on apoptosis, cell migration, and invasion.

Vascular remodeling and extracellular matrix breakdown in the uterine spiral arteries during pregnancy

During pregnancy, trophoblasts invade and transform the maternal spiral arteries that supply blood to the placenta. Recent work has revealed that this process occurs in several stages, and details of the molecular and cellular mechanisms are beginning to emerge, including changes that precede or accompany trophoblastic colonization of the vascular media. Disruption and eventual loss of smooth muscle cells and their associated extracellular matrix are central to physiological transformation. Advances in understanding will lead to the identification of the causative factors involved in failure of remodeling in pathological pregnancies and suggest novel diagnostic and therapeutic avenues.

Gestational trophoblastic neoplasia—pathogenesis and potential therapeutic targets

Gestational trophoblastic neoplasia comprises a unique group of human neoplastic diseases that derive from fetal trophoblastic tissues and represent semiallografts in patients. This group is composed of choriocarcinoma, placental-site trophoblastic tumour, and epithelioid trophoblastic tumour, and many forms are derived from the precursor lesions, hydatidiform moles. Although most patients with gestational trophoblastic neoplasia are cured by chemotherapy and tumour resection, some patients suffer from metastatic diseases that are refractory to conventional chemotherapy. Therefore, new therapeutic regimens are needed to reduce the toxic effects associated with current chemotherapy and to salvage the occasional non-operable patients with recurrent and chemoresistant disease. Until the fundamental biology of gestational trophoblastic neoplasia becomes more clearly understood, development of a new treatment will remain empirical. This review will briefly summarise the recent advances in understanding the molecular aetiology of this group of diseases and highlight the molecules that can be potentially used for therapeutic targets to treat metastatic gestational trophoblastic neoplasia.

Expression of matrix metalloproteinase-2 and mutant p53 is increased in hydatidiform mole as compared with normal placenta

Matrix metalloproteinases (MMPs) are group of enzymes thought to play an important role in trophoblastic and tumor invasion. The aim of our study was to investigate the trophoblastic expression of MMPs and p53 in normal trophoblast and hydatidiform moles (HM). Paraffin sections of 45 specimens, including 14 complete hydatidiform moles (CM), 15 partial hydatidiform moles (PM), 8 atypical partial hydatidiform moles (aPM), and 8 controls were selected. Classification of HM was established on histologic criteria and supported by the DNA ploidy results. Tissue sections from each case were immunostained with monoclonal antibodies, cytokeratin-7, MMP-2, MMP-9, tissue inhibitors of metalloproteinases (TIMP)-1, and p53 wild type (p53wt) and mutant types (mutp53). Staining for cytokeratin-7 revealed a positive reaction in 93% of the samples. MMP-2 was mainly expressed in the syncytiotrophoblast of HM and found in 62% of aPM, 60% PM, and 93% CM. The mutp53 was mainly and focally expressed in syncytiotrophoblastic cells and was found in 63% of aPM, 80% PM, and 93% CM. Expression of MMP-2 and mutp53 was both significantly greater in HM vs control group (P < 0.05) and greater in CM vs PM and aPM (P < 0.05). No significant difference was observed for cytokeratin-7, MMP-9, TIMP-1, and p53wt between the HM subgroups and between HM and control group. MMP-2 and mutp53 are overexpressed in HM as compared with normal trophoblast and might participate in the invasive behavior of the HM.

Nuclear beta-catenin and Ki-67 expression in choriocarcinoma and its pre-malignant form

OBJECTIVE

To study the expression of nuclear beta-catenin and Ki-67 in patients with normal gestation products (NGP), complete hydatidiform moles (CHM), and choriocarcinoma to elucidate their roles in carcinogenesis and their interrelations.

METHODS

Expression of nuclear beta-catenin and Ki-67 was studied by immunohistochemistry using paraffin embedded blocks. Sixty NGP, 60 CHM, and 10 choriocarcinomas were analysed. In addition, approximately 400 trophoblasts each in 40 NGP, 40 CHM, and 10 choriocarcinomas from the same batch of samples were microdissected for quantitative reverse transcriptase polymerase chain reaction (Q-RT-PCR) to compare beta-catenin mRNA concentration among them.

RESULTS

In the chorionic villi of NGP, beta-catenin was consistently expressed in the nuclei of cytotrophoblasts but not syncytiotrophoblasts. Nuclear beta-catenin expression was comparatively reduced in CHM trophoblasts and was absent in choriocarcinoma. By contrast, Ki-67 expression was increased from cytotrophoblasts but not in syncytiotrophoblasts in the chorionic villi of NGP to CHM trophoblasts and choriocarcinoma. Using Q-RT-PCR, beta-catenin mRNA was detected in 10 NGP, 13 CHM, and three choriocarcinoma specimens, with median copy numbers of 43,230, 18,229, and 17,334 per 400 trophoblasts, respectively. A housekeeping gene glyceraldehyde-3-phosphate dehydrogenase (GAPDH) mRNA was detected as a control in the NGP, CHM, and choriocarcinoma specimens, with median copy numbers of 51,300, 54,270, and 97,150 per 400 trophoblasts, respectively. Thus median beta-catenin mRNA values after normalisation were 0.85 in NGP (n = 10), 0.31 in CHM (n = 13), and 0.16 in choriocarcinoma (n = 3).

CONCLUSIONS

Decreased nuclear beta-catenin expression and increased Ki-67 expression may be involved in choriocarcinoma carcinogenesis. The findings also suggest that nuclear beta-catenin may play a role in trophoblast differentiation during normal placental development.

Promoter hypermethylation of multiple genes in hydatidiform mole and choriocarcinoma

The methylation status of genes in hydatidiform mole and choriocarcinoma and its significance is relatively unexplored. We investigated the methylation status of the promoter regions of six genes, p16, HIC-1, TIMP3, GSTP1, death-associated protein kinase (DAPK), and E-cadherin in 54 hydatidiform moles, five choriocarcinomas, and 10 first trimester placenta by methylation-specific polymerase chain reaction (PCR). Immunohistochemical expression of p16, TIMP3, and E-cadherin, and quantitative real-time RT-PCR of p16 was also performed. Among the six genes examined, the promoter region of four genes (E-cadherin, HIC-1, p16, TIMP3) in choriocarcinoma and three genes (E-cadherin, HIC-1, p16) in hydatidiform mole exhibited aberrant methylation whereas none was hypermethylated in normal placenta. There was a significant correlation between methylation and reduced expression of p16, E-cadherin, and TIMP3 (P < 0.001). Fifteen of the 54 patients with hydatidiform mole developed gestational trophoblastic neoplasia requiring chemotherapy. Promoter hypermethylation of p16 alone, or combined with E-cadherin, was significantly correlated to such development (P = 0.001, 0.0005, respectively). Hypermethylation of multiple genes, especially p16, might be related to the subsequent development of gestational trophoblastic neoplasia.

The changes of gene expression profiles in hydatidiform mole and choriocarcinoma with hyperplasia of trophoblasts

The purpose of this study is to investigate changes of gene expression profiles in hydatidiform moles (HM) and choriocarcinoma and to explore causes of trophoblastic hyperplasia. Using cDNA microarray, 4,096 genes were analyzed in two pairs of the tissues of HM versus normal villi and in two pairs of normal primary culture trophoblasts versus JAR cell line of choriocarcinoma. The expressions of two genes in normal villi and HM, as well as in JAR and JEG-3, were examined with the help of immunohistochemistry, immunoblot, and reverse transcriptase-polymerase chain reaction in order to confirm the findings of cDNA microarray. Twenty-four genes were upregulated and 65 genes were downregulated in all HM. Four hundred thirty-three genes were upregulated and 380 genes were downregulated in JAR. Forty-six genes were upregulated in both HM and choriocarcinoma, whereas 13 genes were downregulated. Genes associated with the inhibition of cell proliferation were significantly downregulated, whereas genes associated with cell proliferation, malignant transformation, metastasis, and drug resistance were upregulated. Thymidine kinase-1 (TK-1) and small subunit ribonucleotide reductase (RRM-2) were overexpressed in HM, JAR, and JEG-3. The expressions of TK-1 and RRM-2 in moles were positively correlated with proliferative index of trophoblasts. Our results suggest that altered expression of genes exist in HM and choriocarcinoma. Trophoblastic hyperplasia may be involved in the overexpression of DNA synthetic enzymes.

Expression of matrix metalloproteinases in patients with uterine smooth muscle tumors: an immunohistochemical analysis of MMP-1 and MMP-2 protein expression in leiomyoma, uterine smooth muscle tumor of uncertain malignant potential, and leiomyosarcoma

OBJECTIVE

Matrix metalloproteinases (MMPs) have been suggested to play an important role in tumor invasion and metastasis. We compared the expression of MMP-1 and MMP-2 protein in patients with leiomyoma, uterine smooth muscle tumor of uncertain malignant potential (STUMP), and leiomyosarcoma (LMS).

METHODS

MMP-1 and MMP-2 expression was investigated by immunohistochemistry from paraffin-embedded tissue in 26 patients with leiomyoma, in 24 patients with STUMP, and in 21 patients with LMS.

RESULTS

MMP-1 was expressed in 92% of leiomyomas, in 83% of STUMP, and in 86% of LMS, whereas MMP-2 was expressed in 12% of leiomyomas, in 17% of STUMP, and in 48% of LMS. A statistically significant difference regarding the frequency of MMP-2 expression was observed between LMS and STUMP (P =.025) as well as between LMS and leiomyoma (P =.006), but not between STUMP and leiomyoma (P >.05). Likewise, the staining intensity did significantly differ between LMS and leiomyoma (P =.025), but no statistical significant difference was observed between LMS and STUMP (P >.05) and between STUMP and leiomyoma (P >.05).

CONCLUSION

The stronger MMP-2 expression in patients with LMS compared with STUMP and leiomyoma indicates that this protein might be a marker for tumor invasion or metastasis in patients with uterine LMS. Furthermore, MMP-2 seems to be a useful immunohistochemical parameter to distinguish cases of smooth muscle tumors in which histologic features are ambiguous or borderline. Further studies including larger numbers of patients are necessary to establish MMP-2 as a routine marker for tumor invasion and progression.

Methylation status and expression of E-cadherin and cadherin-11 in gestational trophoblastic diseases

The clinical significance of cadherins in gestational trophoblastic diseases (GTD) is not fully understood. In this study, the expression of E-cadherin and cadherin-11 in 12 normal placentas, 32 cases of hydatidiform mole (HM) including 15 complete HMs and 17 partial HMs, and five choriocarcinomas was investigated by immunohistochemistry and correlated with follow-up of HMs. Cases with available frozen blocks were further analyzed by western blot and semiquantitative reverse transcriptase polymerase chain reaction (RT-PCR). Methylation of E-cadherin was investigated by methylation-specific PCR in six normal first trimester placentas, 19 HMs and their associated deciduas. E-cadherin expression was localized to cytotrophoblast and intermediate trophoblast whereas cadherin-11 was expressed in syncytiotrophoblast, intermediate trophoblast, and decidua. Immunoreactivity of E-cadherin was reduced in choriocarcinoma and complete HM when compared with that in normal first trimester placenta (P < 0.01, P = 0.04). Hypermethylation of E-cadherin was demonstrated in three complete HMs with the lowest level of E-cadherin. Compared with normal first trimester placenta, immunoreactivity of cadherin-11 was higher in complete HM (P = 0.02), but lower in choriocarcinoma (P = 0.02). Such differential expression was confirmed by western blot and semiquantitative RT-PCR. No obvious association was observed between the development of persistent trophoblastic disease with the expression of E-cadherin and cadherin-11.

Effects of Fibronectin, VEGF and Angiostatin on the Expression of MMPs through Different Signaling Pathways in the JEG-3 Cells

PROBLEM

The objective of this study was to evaluate the possible signal pathway of fibronectin (FN), vascular endothelial growth factor (VEGF) and angiostatin (AS) on the expression of matrix metalloproteinases (MMPs) in JEG-3 cells.

METHODS OF STUDY

JEG-3 cells were cultured and were examined for the effect of FN, VEGF and AS on the expression of MMPs by immunocytochemistry, gelatin zymography, Western blot analysis and reverse transcription-polymerase chain reaction (RT-PCR).

RESULTS

We found that up-regulation of the expression of MMPs was induced by FN and VEGF through the focal adhesion kinase (FAK)/mitogen-activated protein kinase (MAPK) and Flt-1/p38SAPK/MAPKAPK2 signaling pathways, respectively. Furthermore, AS down-regulated the expression of MMPs through the integrin alphaVbeta3/FAK signaling pathway independent of the integrin-binding motif Arg-Gly-Asp (RGD).

CONCLUSION

These data indicate that the expression of MMPs is regulated by many independent factors (such as FN, VEGF and AS) through different signaling pathways which influence the behavior of trophoblast cells.

The matrix metalloproteinase system: changes, regulation, and impact throughout the ovarian and uterine reproductive cycle

The ovary and uterus undergo extensive tissue remodeling throughout each reproductive cycle. This remodeling of the extracellular environment is dependent upon the cyclic hormonal changes associated with each estrous or menstrual cycle. In the ovary, tissue remodeling is requisite for growth and expansion of the follicle, breakdown of the follicular wall during the ovulatory process, transformation of the postovulatory follicle into the corpus luteum, as well as the structural dissolution of the corpus luteum during luteal regression. In the uterus, there is extraordinary turnover of the endometrial connective tissue matrix during each menstrual cycle. This turnover encompasses the complete breakdown and loss of this layer, followed by its subsequent regrowth. With implantation, extensive remodeling of the uterus occurs to support placentation. These dynamic changes in the ovarian and uterine extracellular architecture are regulated, in part, by the matrix metalloproteinase (MMP) system. The MMP system acts to control connective tissue remodeling processes throughout the body and is comprised of both a proteolytic component, the MMPs, and a regulatory component, the associated tissue inhibitors of metalloproteinases. The current review will highlight the key features of the MMPs and tissue inhibitors of metalloproteinases, focus on the changes and regulation of the MMP system that take place throughout the estrous and menstrual cycles, and address the impact of the dynamic tissue remodeling processes on ovarian and uterine physiology.

Osteopontin is down-regulated in hydatidiform mole

OBJECTIVE

Osteopontin (OPN) is a glycoprotein of the extracellular matrix that can bind to different types of receptors including integrins and CD44 receptors. Multiple binding affinity enables OPN to play a role in many physiological and pathological processes. OPN contributes to tumorigenesis in several types of cancers. OPN is also expressed by the endometrium and by trophoblast cells of the chorionic villus in human placenta, where OPN may regulate implantation and placentation in early pregnancies by promoting cell-cell interactions, adhesion, spreading, and migration of trophoblast. Our purpose was to determine the expression of OPN mRNA and protein in hydatidiform mole and in normal placenta of comparable gestational age.

METHODS

A total of 13 fresh tissues from complete hydatidiform moles, 2 from partial hydatidiform moles, and 9 from normal placentas were analyzed by performing quantitative real-time PCR on microdissected trophoblast cells and immunohistochemistry on frozen sections of tissue.

RESULTS

Our results showed significantly lower expression of OPN mRNA and protein in hydatidiform mole, and in particular complete mole (P = 0.001 by real-time PCR and P < 0.001 by immunohistochemistry) as compared to nermal placenta.

CONCLUSION

Although precise molecular mechanisms of gestational trophoblastic diseases have not yet been determined, down-regulation of osteopontin may play an important role in the pathogenesis of molar pregnancy.

Effect of matrigel on human extravillous trophoblasts differentiation: modulation of protease pattern gene expression

The human placenta is characterized by extensive trophoblast invasion of the uterus. Indeed, extravillous cytotrophoblast cells invade the decidua and the upper third of uterine spiral arteries in the myometrium. This invasion is reflected in situ by the expression of specific markers. In order to study this invasion process, we have established an in vitro culture model of human extravillous trophoblast isolated from first trimester chorionic villi. The aim of this study was to investigate the effect of a composite matrix, the Matrigel required for the culture of this homogenous population of extravillous trophoblasts (EVCT), on their in vitro differentiation. The effect of Matrigel was studied on different markers characterized by immunocytochemistry and by real-time polymerase chain reaction assay of transcripts. In addition, the expression of 12 different matrix metalloproteases and their inhibitors were investigated. We show that human extravillous cytotrophoblasts acquire an invasive phenotype on Matrigel associated with a specific pattern of protease gene expression. This in vitro model will be of interest to study the cellular mechanisms involved in abnormal trophoblast invasion observed in poor placentation and preeclampsia.

Current understandings of the molecular genetics of gestational trophoblastic diseases

Gestational trophoblastic disease (GTD) is a heterogeneous group of diseases characterized by abnormally proliferating trophoblastic tissues. This includes partial and complete hydatidiform moles, invasive mole, choriocarcinoma and placental site trophoblastic tumour. Cytogenetic studies revealed that hydatidiform moles contain either solely (as in complete moles) or an excess (as in partial moles) of paternal contribution to the genome. Genomic imprinting is believed to play a pivotal role in the pathogenesis of hydatidiform moles. However its precise role and mechanism remains poorly understood. Hydatidiform mole carries a potential of malignant transformation. Similar to other human cancers, malignant transformation in gestational trophoblastic tumours is likely a multistep process and involves multiple genetic alterations including activation of oncogenes and inactivation of tumour suppressor genes. In addition, expression of telomerase activity, altered expression of cell--cell adhesion molecules and abnormal expression of matrix metalloproteinases have also been reported in GTD. These represent disruption of the delicate balance and regulation of cellular processes including proliferation, differentiation, apoptosis and invasion. The significance of these alterations in the pathogenesis and malignant transformation of gestational trophoblastic diseases is reviewed in this paper.

Gestational trophoblastic diseases: new standards for therapy

Gestational trophoblastic disease (GTD) is a spectrum of rare neoplastic conditions that are highly curable, even in the presence of widely metastatic disease. These diseases vary from partial hydatidiform mole, which rarely metastasizes and infrequently requires treatment with chemotherapy, to choriocarcinoma, for which multi-agent chemotherapy is the standard treatment. Much has been learned regarding the epidemiology of this disease, and our understanding of the genetics underlying GTD is rapidly expanding. As technology such as ultrasonography and sensitive tests for beta-human chorionic gonadotropin have evolved, the presentation of molar pregnancy has significantly changed, although the incidence of persistent GTD has not decreased. This review highlights these recent advancements in the epidemiology, genetics, diagnosis, and treatment of gestational trophoblastic disease.